The last bike I picked up was from one of the wholesale clubs. I think I paid 199 ish in late 1990s, it got me all through my college career and I'm actually still riding it approx 4 days a week for regular exercise. Can't recall the brand but it was one that was made in Taiwan, I do recall that.
Watch CL and the other local for sale apps for possible bargain.
You mind find one that was working when it was stored 20 years ago that just needs a new fuse!